Silicon-containing film etching method, computer-readable storage medium, and silicon-containing film etching apparatus

Abstract

There is provided a method of etching a silicon-containing film formed on a substrate, comprising: supplying an etching gas including a fluorine-containing gas having a smaller molecular weight than ClF3 to the silicon-containing film; and controlling etching amounts at a central portion and an outer peripheral portion of the silicon-containing film by controlling a flow velocity of the etching gas.

What is claimed is: 
     
         1 . A method of etching a silicon-containing film formed on a substrate, comprising:
 supplying an etching gas including a fluorine-containing gas having a smaller molecular weight than ClF 3  to the silicon-containing film; and   controlling etching amounts at a central portion and an outer peripheral portion of the silicon-containing film by controlling a flow velocity of the etching gas.   
     
     
         2 . The method of  claim 1 , further comprising:
 supplying the etching gas to the silicon-containing film formed on the substrate for setting an etching condition to etch the silicon-containing film;   subsequently, measuring an in-plane distribution of an etching amount of the etched silicon-containing film; and   subsequently, setting the flow velocity of the etching gas based on the measured in-plane distribution of the etching amount.   
     
     
         3 . The method of  claim 1 , further comprising:
 controlling the flow velocity of the etching gas based on a state of the silicon-containing film which has been subjected to an additional process performed separately from the etching of the silicon-containing film.   
     
     
         4 . The method of  claim 3 , wherein the additional process is a process performed before the etching, and
 the additional process includes feed-forward controlling the flow velocity of the etching gas based on the state of the silicon-containing film.   
     
     
         5 . The method of  claim 3 , wherein the additional process is a process performed after the etching, and
 the additional process includes feed-back controlling the flow velocity of the etching gas based on the state of the silicon-containing film.   
     
     
         6 . The method of  claim 1 , wherein the step of controlling the flow velocity of the etching gas includes controlling a flow rate of the etching gas or an internal pressure of a processing space in which the etching is performed. 
     
     
         7 . The method of  claim 1 , wherein the fluorine-containing gas has a molecular weight of 38 or less. 
     
     
         8 . The method of  claim 1 , wherein the silicon-containing film is a silicon germanium film, and
 the etching gas includes an F 2  gas for etching the silicon germanium film.   
     
     
         9 . The method of  claim 1 , wherein the silicon-containing film is a silicon film, and
 the etching gas includes an F 2  gas and a basic gas for etching the silicon film.   
     
     
         10 . The method of  claim 1 , further comprising:
 supplying the etching gas to the silicon-containing film from above the substrate; and   discharging the etching gas from a lateral side and a lower side of the substrate.   
     
     
         11 . A non-transitory computer-readable storage medium storing a program that operates on a computer of a controller for controlling an etching apparatus such that the method of  claim 1  is performed by the etching apparatus. 
     
     
         12 . An apparatus of etching a silicon-containing film formed on a substrate, comprising:
 a chamber in which the substrate is accommodated;   a gas supply part configured to supply an etching gas including a fluorine-containing gas having a smaller molecular weight than ClF 3  to the silicon-containing film;   an exhaust part configured to discharge the etching gas inside the chamber; and   a controller configured to control the gas supply part and the exhaust part,   wherein the control part controls etching amounts at a central portion and an outer peripheral portion of the silicon-containing film by controlling a flow velocity of the etching gas.